KR100339605B1 - Automatic gain control circuit - Google Patents

Automatic gain control circuit Download PDF

Info

Publication number
KR100339605B1
KR100339605B1 KR1020000064259A KR20000064259A KR100339605B1 KR 100339605 B1 KR100339605 B1 KR 100339605B1 KR 1020000064259 A KR1020000064259 A KR 1020000064259A KR 20000064259 A KR20000064259 A KR 20000064259A KR 100339605 B1 KR100339605 B1 KR 100339605B1
Authority
KR
South Korea
Prior art keywords
voltage
amplifier
frequency signal
gain control
integrator
Prior art date
Application number
KR1020000064259A
Other languages
Korean (ko)
Inventor
Young Tae Noh
Original Assignee
Lg Electronics Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Lg Electronics Inc filed Critical Lg Electronics Inc
Priority to KR1020000064259A priority Critical patent/KR100339605B1/en
Application granted granted Critical
Publication of KR100339605B1 publication Critical patent/KR100339605B1/en

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Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G3/00—Gain control in amplifiers or frequency changers
    • H03G3/20—Automatic control
    • H03G3/30—Automatic control in amplifiers having semiconductor devices
    • H03G3/3036—Automatic control in amplifiers having semiconductor devices in high-frequency amplifiers or in frequency-changers
    • H03G3/3042—Automatic control in amplifiers having semiconductor devices in high-frequency amplifiers or in frequency-changers in modulators, frequency-changers, transmitters or power amplifiers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G3/00—Gain control in amplifiers or frequency changers
    • H03G3/20—Automatic control
    • H03G3/30—Automatic control in amplifiers having semiconductor devices
    • H03G3/3052—Automatic control in amplifiers having semiconductor devices in bandpass amplifiers (H.F. or I.F.) or in frequency-changers used in a (super)heterodyne receiver
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G2201/00—Indexing scheme relating to subclass H03G
    • H03G2201/10—Gain control characterised by the type of controlled element
    • H03G2201/106—Gain control characterised by the type of controlled element being attenuating element
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G2201/00—Indexing scheme relating to subclass H03G
    • H03G2201/20—Gain control characterized by the position of the detection
    • H03G2201/204—Gain control characterized by the position of the detection being in intermediate frequency

Landscapes

  • Control Of Amplification And Gain Control (AREA)

Abstract

PURPOSE: An automatic gain control circuit is provided to prevent an error due to a plurality of differential amplifiers and a damage of an attenuator due to a negative value output signal of an integrator, by setting a sum value of a strength and a gain control voltage of an intermediate frequency signal as a reference voltage of the integrator and a power supply voltage of the integrator as a positive voltage. CONSTITUTION: The first log amplifier(100) receives an intermediate frequency signal divided through a signal divider(1) and converts the strength of the intermediate frequency signal into a direct current voltage. An adder(200) adds a gain control voltage to a direct current level output from the first log amplifier(100). An inverse amplifier(300) inverts and amplifies an output of the adder(200). The second log amplifier(400) receives a radio frequency signal from a final radio frequency amplifier(10) and converts the strength of the radio frequency signal into a direct current voltage. An integrator(500) receives a voltage from the inverse amplifier(300) as a reference voltage and outputs an integration value of an output voltage of the second log amplifier to an attenuator(9).
KR1020000064259A 2000-10-31 2000-10-31 Automatic gain control circuit KR100339605B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020000064259A KR100339605B1 (en) 2000-10-31 2000-10-31 Automatic gain control circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020000064259A KR100339605B1 (en) 2000-10-31 2000-10-31 Automatic gain control circuit

Publications (1)

Publication Number Publication Date
KR100339605B1 true KR100339605B1 (en) 2002-06-05

Family

ID=37480195

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020000064259A KR100339605B1 (en) 2000-10-31 2000-10-31 Automatic gain control circuit

Country Status (1)

Country Link
KR (1) KR100339605B1 (en)

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